Research ArticleImpact of Dietary 𝛼-Lipoic Acid on Antioxidant Potential ofBroiler Thigh Meat
Muhammad Issa Khan,1,2 Komal Shehzad,2 Muhammad Sajid Arshad,3 Amna Sahar,2
Muhammad Asim Shabbir,2 and Muhammad Saeed2
1College of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea2National Institute of Food Science and Technology, University of Agriculture, Faisalabad 38040, Pakistan3Institute of Home and Food Sciences, Government College University, Faisalabad 38000, Pakistan
Correspondence should be addressed to Muhammad Issa Khan; [email protected]
Received 9 November 2014; Revised 2 February 2015; Accepted 4 February 2015
The lipid oxidation depressed themeat quality and can be triggered during industrial processing.The current study was designed toassess the antioxidant activity of thigh meat and meat products enriched with natural antioxidants (𝛼-lipoic acid and 𝛼-tocopherolacetate). Broilers (21 days) were fed on feed supplemented with varying 𝛼-lipoic acid and constant concentration of 𝛼-tocopherolacetate for 3 weeks. Birds were slaughtered at the age of 42 days and meat samples were collected and stored for further analysisand product preparation. TPC and DPPH value indicated that meat of broilers receiving 100mg of 𝛼-lipoic acid with 200mg of𝛼-tocopherol acetate/kg of feed possessed the highest antioxidant activity. TBARS and peroxides values were found to be lowerfor meat of broilers fed on different levels of 𝛼-lipoic acid. The antioxidants (lipoic acid and tocopherol) enrichment in meathelps to reduce PUFAs. A similar lipid stability trend was observed in nuggets prepared from broiler thigh meat and maximumsensory evaluation scores for nuggets prepared from thigh meat of broilers having the highest dose of lipoic acid. The lipoic acidsupplementation in feed enhances the antioxidant capacity of thigh meat and meat products.
1. Introduction
Meat is a vital product in human diet having balance chemicalcomposition, high biological value, digestibility, and dietarypotential. Broiler meat being low in fat and cholesterolis usually considered healthier than other animal proteinsources, especially redmeats ofmammalian origin [1]. Healthand nutritional aspects of broiler meat have led to an increasedemand of broiler meat in the whole world. The householdincome and price of substitute meats relative to flavor andtastiness are other factors that contribute to rising demandof broiler meat. Likewise, awareness of consumers on thehealth and nutritional value of meat also increases withpopulation growth and food consumption trends [2]. Meatquality is generally judged through its appearance, texture,color, aroma, and taste. The color and taste both significantlyaffect the purchasing behavior and eating preferences ofconsumers [3]. Raw broiler meat has little blood-like taste
while containing a number of natural components whichupon heating generate a large number of volatile compoundsresponsible for the cooked meat aroma and flavor throughthermal degradation of lipids and thiamine, breakdown ofpeptides and amino acids, and interaction between aminoacids and sugars. Besides, pre- and postslaughter factors alsohave significant effect on broiler meat texture and flavor[4]. Lipid oxidation is considered as one of the primarycauses of quality deterioration and flavor defector in meatsand other lipid containing food products [5]. Many timesmyoglobin pigment oxidation is positively correlated withlipid oxidation leading to color as well as odor defects of thefreshmeat [6]. Broiler thighmuscles are considered oxidativewith more mitochondria and a higher content of myoglobincompared to glycolytic breast muscles and utilize fatty acidsas energy source more than glycogen indicating the presenceof higher amount of fatty acids in this part of broiler meat [7].Similarly, cooking is a significant factor that accelerates lipid
Hindawi Publishing CorporationJournal of ChemistryVolume 2015, Article ID 406894, 8 pageshttp://dx.doi.org/10.1155/2015/406894
peroxidation and volatile production in meat by disruptingmuscle cell structure, inactivating antioxidant enzymes andother antioxidant compounds, and releasing iron from hemepigments therefore enhancing fat oxidation in cooked meat[8]. Antioxidant feed supplementation is an effective methodto control and preserve the oxidative changes in meat andmeat products [9]. In broiler chickens, 𝛼-tocopherol feedsupplementation not only increases vitamin E concentrationin the tissue, but also reduces the rancidity levels in broilermeat andmaintains redness of tissues [10].While alpha lipoicacid (ALA) being a natural antioxidant acts as an NADHoxidase inhibitor to block oxidant production, diminisheshepatic fatty acid oxidation in broiler chickens, and reducesthe ketone body production. Dietary ALA supplementationalso recycles the vitamin E contents of the muscles andpotentially reduces the incidence of PSE (pale, soft, andexudative) meat [11]. Whenever vitamin E and lipoic acidare used together, their antioxidant properties improve aslipoic acid recycles vitamin E and lowers the oxidative stressand protects immune cells [12]. The objective of the presentresearch was to evaluate the effect of alpha lipoic acid andalpha tocopherol acetate as feed supplement in broiler dietand to assess the oxidative stability of raw and processed thighmeat and meat product.
2. Materials and Methods
2.1. Procurement of Birds and Feed Ingredients. 150 chicks(Hubbard) were purchased from Hi-Tech Feeds (Pvt.) Ltd.,Pakistan. The birds were randomly selected having the sameweight and were kept in room reserved for research atUniversity of Agriculture, Faisalabad, Poultry Farm havingpens of 4 × 3 × 1.5 feet. The room and the pens werecleaned thoroughly, white-washed, and disinfected. Therewere 5 groups and 3 replicates for each group. Each replicatecarried 10 birds. The experimental birds were reared up tosix weeks. For the first three weeks, the chicks were fed onbasal feed and the following three weeks chicks were fed onfeed supplemented with different levels of alpha lipoic acid(T0: control; T
1: 25mg/kg; T
2: 50mg/kg; T
3: 75mg/kg; T
4:
100mg/kg) with constant level of alpha tocopherol acetate(200mg/kg).
2.2. Sample Collection and Preparation. The birds wereslaughtered according to Islamic halal ethical guidelines. Theprotocol for this method was approved in our institute. Atthe age of 6 weeks thigh meat samples of each treatmentwere kept in polyethylene plastic bags and stored at −18∘Ctill further analysis. 5 gram thigh meat sample was takenin 50mL polypropylene tube having a cap and sample washomogenized by using phosphate buffer and glycerol (20%)pH (7.4) in 1 : 10 ratio with the help of homogenizer. Thehomogenized thigh meat sample was centrifuged at 1000×gfor ten minutes and 20-second rest was given to dissipatethe heat generated during homogenization. Supernatant ofeach treatment was collected and stored at −18∘C for furtheranalysis [13].
2.3. Assessment of Antioxidant Status in Raw Thigh Meat.Total phenolic contents of thigh meat were determinedby a procedure followed by Senevirathne et al. [14]. Theantioxidant activity of thigh meat was assessed by measuringits DPPH stable radicals scavenging abilities by the methodas described by Brand-Williams et al. [15]. Oxidative stabilityof broiler thigh meat sample was determined by measuringmg of malondialdehyde per kg of meat following the methoddescribed by Asghar et al. [16].
2.4. Quantification of Alpha Lipoic Acid by Using HPLC. Thefrozen sample (500mg) was ground in mortar pestle for theisolation of the alpha lipoic acid from meat. The meat tissuewas homogenized with 2mL of m-phosphoric acid (20%w/v). After 2-minute vortex of sample, 3mL of n-hexane and250 𝜇L isopropanol were added and then tube was shaken for30 minutes for the extraction of alpha lipoic acid. The tubewas centrifuged at 1500 rpm and was collected the upper n-hexane layer in vial. We repeated this step twice and pooledthe n-hexane layer [17]. The mobile phase was prepared byusing acetonitrile and water (80 : 20). The sample was elutedisocratically with 1mL/minute of flow rate. The standards ofalpha lipoic acid were prepared by dissolving alpha lipoicacid in n-hexane as a stock solution (30 𝜇g/mL), wherethe further dilutions were made 10 𝜇g/mL, 60 𝜇g/mL, and90 𝜇g/mL, respectively. A Shimadzu (Kyoto, Japan) HPLCsystem consisting of two LC-10AD pumps, an SCL-10Asystem controller, a manual injector, and a degasser (DGU-12A) was used. The analytical column for reversed-phasechromatography was a 5𝜇m particle size Shim-Pack CLC(C18) column, 15 cm × 4.6mm × 5 𝜇m (Shinwa Chemicals,Kyoto, Japan). The columns were maintained at 25∘C by aCTO-10A column oven (Shimadzu). The effluent was mon-itored by SPD-l0AVYP UV-Vis and RF-10AXL fluorescencedetectors equipped with an 8 𝜇L flow cell (Shimadzu). Thefluorescence detector was set at 343 nm.
2.5. Quantification of Alpha Tocopherol by Using HPLC. One-gram sample was taken in centrifuge tube (30mL) for alphatocopherol extraction. Tissue was solubilized when 1.5mLof urea (6M) was added in tube. The tissue of meat wasdisintegrated when 1mL of 0.1M sodium dodecyl sulphate(SDS) solution was added in tube. The 4mL of ethyl alcohol(EtOH 95%) containing 1% pyrogallol was added in tube fordeproteination and freeing of alpha tocopherol from themeattissue. The phase separation was facilitated by adding 10mLof petroleum ether in tube and vortex for 2 minutes. Thenthe tube was centrifuged at 2000 rpm for 5 minutes. Theupper solvent layer was transferred in a vial. This step wasrepeated two times for complete extraction of alpha toco-pherol. Evaporate the pooled solvent phase under nitrogento dryness. 500 𝜇L EtOH (mobile phase) was added in tube;tight the screw and vortex the tube for 1 minute at 45∘C (inwater bath) to facilitate the solubilization of alpha tocopherolin mobile phase. The sample was filter, using Anspec H1056microfilter and centrifugation at 2000 rpm for 5 minutes.The filtrate was collected in the vial and stored in the darkplace to protect degradation of tocopherol in the sample.The
standard of alpha tocopherol was prepared by dissolving l 𝜇gof alpha tocopherol in lmL of methanol. Further dilutionsof 2𝜇g/mL, 3𝜇g/mL, and 4 𝜇g/mL were made, respectively.A Shimadzu (Kyoto, Japan) HPLC system consisting of twoLC-10AD pumps, an SCL 10A system controller, manualinjection syringe, and a degasser (DGU-12A) was used. Theanalytical column for reversed-phase chromatography wasa 5 𝜇m particle size Shim-Pack CLC (C18) column, 15 cm× 4.6mm × 5 𝜇m (Shinwa Chemicals, Kyoto, Japan). Thecolumns were maintained at 25∘C by a CTO-10A columnoven (Shimadzu). The effluent was monitored by SPD-10AVvp UV-Visible detectors equipped with an 8 𝜇L flow cell(Shimadzu). The UV-Vis detector was set at 290 nm. A lineargradient elution from methanol (100%) was adopted. Theflow rate of the mobile phase was 1.0mL/minute. The peakareas obtained from detector were calculated using Vstationchromatography software (GL Science, Tokyo, Japan). Thismethod was modified form of Asghar et al. [18].
2.6. Peroxide Value. Oxidation was evaluated by peroxidevalue. Peroxide value of the oil recovered from thigh sampleswas determined by a procedure described by Shantha andDecker [19]. The lipid sample (5.0 g) was treated with 25mLof organic solvent mixture (chloroform/acetic acid, 2/3: v/v).The mixture was shaken vigorously, followed by addition of1mL of saturated potassium iodide solution. The mixturewas kept in the dark for 5min before adding 75mL ofdistilled water. The mixture was titrated against standardized0.01N sodium thiosulfate solution till yellow color almostdisappeared. Then 0.5mL of starch solution (1% w/v) wasadded to the mixture, as an indicator, shaken vigorously, andcarefully titrated till blue color just disappeared.
2.7. Fatty Acids Profile ofThighMeat. Free fatty acids contentsin oil recovered from thigh samples were quantitatively mea-sured through gas chromatography coupled with flame ion-ization detector (GC-FID) according to a method describedby [20]. 100mg of oil sample was saponified with 100 𝜇L2N KOH, and 3mL hexane was added to the mixture. Themixture was vigorously shaken with a vortex for 1min andthen centrifuged at 5000 rpm for 5min and left overnightat room temperature for phase separation. The top hexanelayer containing methylated fatty acids was analyzed for fattyacids composition using a GC. Gas Chromatograph (AgilentTechnologies, 6890N) equipped with an autosampler, flame-ionization detector (FID), and a HP-5 column (Silica 30m× 0.25 film thickness, Hewlett Packard Co.) was used forfatty acids separation. A ramped oven temperature condition(180∘C for 2.5min, increased to 230∘C at 2.5∘C/min andthen held at 230∘C for 7.5min) was used. Temperatures ofboth inlet and detector were 280∘C. Helium was the carriergas at linear flow of 1.1mL/min linearly. Detector (FID) air,hydrogen gas, and make-up gas (He) flows were 350, 35,and 43mL/min, respectively. Fatty acids were identified bythe retention time of known standards using Agilent Chem.Station software. Relative quantities were expressed as weight% of total fatty acids.
2.8. Product Development. The raw meat samples stored at−18∘C were used to prepare nuggets for the assessment offrying effect on the oxidative stability of processed products.
2.9. Analysis of Thigh Nuggets. Oxidative stability of nuggetssamples was determined by measuring mg of malondialde-hyde per kg of meat by following the method described byAsghar et al. [16]. Peroxide value of the oil recovered fromnuggets samples was determined by a procedure described inShantha and Decker [19].
2.10. Sensory Evaluation of Nuggets. The sensory evaluationof thigh nuggets for color, taste, flavor, appearance, andoverall acceptability was carried on 9-point hedonic scale toanticipate the acceptability of meat products on quality bases.
2.11. Statistical Analysis. The data obtained from each treat-ment was subjected to statistical analysis to determine thelevel of significance by the factorial design (2-way interac-tion) described by Steel et al. [21] by using the softwarepackage (statistic 8).
3. Results and Discussion
3.1. Antioxidant Capacity and Lipoid Oxidation ofThighMeat.The antioxidant activity of the tissue is assessed by its totalphenolic acid; the higher the total phenolic contents, thehigher the free radical scavenging activity. Supplementa-tion of biological antioxidants, that is, different level of 𝛼-lipoic acid with constant 𝛼-tocopherol acetate, significantlyincreased the phenols content with the increase in 𝛼-lipoicacid (Table 1). The highest TPC (61.28 ± 2.1mg of GAE/g)was observed in meat of broiler fed on maximum amountof supplemented 𝛼-lipoic acid (T
4) while the lowest TPC
(49.03 ± 1.9mg of GAE/g) in broiler meat fed o ncontrolfeed (T
0).Arshad at al. [22] reported an increase in level
of total phenolic contents in microsomal fraction of thighmeat with increase in 𝛼-lipoic acid concentration in feed.Thetotal phenolic contents of thigh meat decreased during 60-day storage of meat from 59.1 ± 2.8mg of GAE/g (0 day)to 50.73 ± 1.4mg of GAE/g (60 days). It is evident fromresults of DPPH free radicals scavenging assay of thigh meatthat free radical scavenging activity of broiler thigh meat issignificantly influenced by the antioxidant supplementationof broiler feed (Table 1).The highest DPPHpercent inhibitionvalues of thigh samples were observed in T
4(81.80 ± 3.6%)
containing maximum amount of alpha lipoic acid and lowestinhibition (71.92 ± 2.4%) was observed for control samples(T0). DPPH percent inhibition values were observed for
broiler fed on control diet. These findings are in agreementwith previous study of Fasseas et al. [23] who concluded thatvitamin E and sage extract increased the antiradical power ofmeat more than control treatment. These findings are also ingood agreement withMin et al. [24] who reported that DPPHradical scavenging activities of thigh meat did not decreasesignificantly during storage. Lipid peroxidation is measureof malondialdehyde compounds formed during autoxidationof lipid in meat tissue. It is obvious from results that the
Results are presented as mean ± SD (𝑛 = 3), whereas results in the same column with no superscripts in common differ significantly at 𝑃 < 0.01.T0: control, T1: control + 200mg vitamin E + 25mg 𝛼-lipoic acid/kg feed, T2: control + 200mg vitamin E + 50mg 𝛼-lipoic acid/kg feed, T3: control + 200mgvitamin E + 75mg 𝛼-lipoic acid/kg feed, and T4: control + 200mg vitamin E + 100mg 𝛼-lipoic acid/kg feed.
highest TBARS value (0.284 ± 0.02 𝜇gMDA/g) of thigh meatwas recorded for meat sample of broilers fed on control diet(T0) while the lowest TBARS value (0.208 ± 0.04 𝜇gMDA/g)
was found for meat sample of broilers fed on feed con-taining 100mg ALA/Kg feed (T
4) (Table 2). The increase in
TBARS value was observed with the progression of storageperiod. Botsoglou et al. [25] showed that dietary antioxidantssupplementation significantly reduces lipid oxidation duringfrozen storage and subsequent refrigeration. The decreasein TBARS values was observed by Fernandez et al. [26]and Cardenia et al. [27] if antioxidants are incorporatedinto broiler meat during storage. The peroxide value is usedto detect the oxidation of unsaturated fatty acids or moreaccurately determining the oxidation state of fatty acids. Itis evident from the data that peroxide values for differenttreatments during storage varied significantly (𝑃 < 0.01).The highest peroxide value (1.88 ± 0.04meq O
2/kg of fat)
was observed in sample after 2 months of storage while thelowest value (0.69 ± 0.06meq O
2/kg of fat) was recorded
at the start of experiment. As depicted in data the highestperoxide value (1.88 ± 0.04meq O
2/kg of fat) was found in
thigh meat of broiler fed on control diet (T0) while the lowest
peroxide value (0.69 ± 0.06meq O2/kg of fat) was observed
in treatment T4(100mg lipoic acid/Kg feed) at the end of
storage (60 days) (Table 2). Levermore [28] reported thatperoxide formation during storage depends on presence ofantioxidants, length of storage, and quality of lipid and rateof formation increases with passage of time. The findings ofresearch are in agreement with Gheisari [29] observationsthat peroxide value increased during refrigerated storage ofmeat.
3.2. Alpha Lipoic Acid and Alpha Tocopherol Contents. Alphalipoic acid is a novel antioxidant having lipid lowering effectwhile exogenous supply of 𝛼-lipoic acid appears to imparta variety of significant positive effects in biological systemincluding free radical scavenging potential [30]. Alpha lipoicacid and alpha tocopherol contents varied significantly (𝑃 <0.01) among different treatments. The highest lipoic acidcontents (49.1±3.7 𝜇g/g) were reported at the start of storagewhile the lowest contents (42.1±3.7 𝜇g/g)were recorded at theend of storage period (60 days) (Table 3). The data explicatedthat the highest lipoic acid contents (69.40±4.8 𝜇g/g) of thigh
meat were recorded in birds getting higher level of dietarylipoic acid (T
4) while the lowest lipoic acid contents (22.17 ±
1.5 𝜇g/g) were observed in broilers fed on control diet. Theseresults are in agreement with previous findings of Parveen etal. [31] who reported that the deposition of 𝛼-lipoic acid inthigh muscles increases with progressive increasing of the 𝛼-lipoic acid in the feed. The gradual increase in the 𝛼-lipoicacid concentration increases the deposition of 𝛼-tocopherol,thus improving the antioxidant status of meat as reportedby Arshad et al. [22]. Decrease in lipoic acid concentrationupon storage may be due to short-term incubation and rapiduptake by tissue or cells [32]. The tocopherol contents varyfrom 49.4±3.9 𝜇g/g to 109.3±6.8 𝜇g/g for different treatments.The highest tocopherol contents (79.28 ± 5.6 𝜇g/g) for alltreatments were reported in the first day of storage while thelowest value (74.93±7.6 𝜇g/g) for all treatments was recordedat 2nd month storage. Similarly, it is clear from data that thehighest tocopherol value (111.84±4.9 𝜇g/g) of thighmeat wasrecorded with treatment T
4while the lowest tocopherol value
(47.75 ± 4.2 𝜇g/g) was found in treatment T0at the end of
storage study (Table 3). It can be concluded from the aboveresults that T
4containing 200mg 𝛼-tocopherol acetate +
100mg 𝛼-lipoic acid exhibited more deposition of tocopherolin thigh muscles as compared with T
0(control) during 2-
month storage study. Alpha tocopherol contents also increasewith an increase in the level of ALA broiler feed. Our resultsdepicted the fact that alpha lipoic acid has positive impact onalpha tocopherol contents, which is also in line with Arshadet al. [22].
3.3. Fatty Acid Profile of Thigh Meat. The fatty acid profile(mg/100 g) results related to broiler thigh meat revealedlauric acid (C-12) varying from 0.027 to 0.021 (mg/100 g),myristic acid (C-14) varying from0.85 to 0.80 (mg/100 g), andpalmitic acid (C-16) varying from 29.79 to 26.14 (mg/100 g)in broiler thighs at different 𝛼-lipoic acid concentrationwith constant 𝛼-tocopherol acetate concentration indicat-ing a decrease in SFAs values due to these antioxidants’supplementation. However, values of arachidonic acid (C-20:4) ranged from 0.78 to 0.75 (mg/100 g), eicosapentaenoicacid (C-20:5) ranged from 0.068 to 0.05 (mg/100 g), anddocosahexaenoic acid (C-22:6) ranged from 0.35 to 0.31(mg/100 g), respectively, showing a decrease in these PUFAs
Results are presented as mean ± SD (𝑛 = 3), whereas results in the same column with no superscripts in common differ significantly at 𝑃 < 0.01.T0: control, T1: control + 200mg vitamin E + 25mg 𝛼-lipoic acid/kg feed, T2: control + 200mg vitamin E + 50mg 𝛼-lipoic acid/kg feed, T3: control + 200mgvitamin E + 75mg 𝛼-lipoic acid/kg feed, and T4: control + 200mg vitamin E + 100mg 𝛼-lipoic acid/kg feed.
Table 3: Alpha lipoic acid content (𝜇g/g) and alpha tocopherol content (𝜇g/g) in thigh meat.
Groups Alpha lipoic acid content (𝜇g/g) Alpha tocopherol content (𝜇g/g)Day 0 Day 30 Day 60 Mean Day 0 Day 30 Day 60 Mean
Results are presented as mean ± SD (𝑛 = 3), whereas results in the same column with no superscripts in common differ significantly at 𝑃 < 0.01.T0: control, T1: control + 200mg vitamin E + 25mg 𝛼-lipoic acid/kg feed, T2: control + 200mg vitamin E + 50mg 𝛼-lipoic acid/kg feed, T3: control + 200mgvitamin E + 75mg 𝛼-lipoic acid/kg feed, and T4: control + 200mg vitamin E + 100mg 𝛼-lipoic acid/kg feed.
(Table 4). It is evident from the findings that concentration ofPUFAs decreases with increase in lipoic acid concentration.The same trend of a decrease in PUFAs was observed by Celikand Ozkaya [33] using the same antioxidants.The decreasingtrend of SFAs and MUFAs is in agreement with results ofCortinas et al. [34] who observed a decreasing trend inSFAs and MUFAs in thigh meat with 𝛼-tocopherol acetatesupplementation in feed. The changing trend in fatty acidscomposition is in linewith findings of Kolsarıcı et al. [35] whostored mechanically deboned chicken meat for 4 months andwith results of Bou et al. [36] who observed the same trend instored white and darkmixedmeat for 5months at −20∘C.Thesame trend was found in the findings of Arshad et al. [13, 37]who found that using 𝛼-lipoic acid decreases the fatty acidsprofile in chicken thigh meat.
3.4. TBARS Values and POV of Thigh Meat Nuggets. TheTBARS values of different treatments for broiler thighnuggets varied significantly (𝑃 < 0.01). Highest TBARSvalue (0.515 ± 0.04 𝜇gMDA/g) of broiler thigh nuggetswas recorded with control samples (T
0) while the lowest
TBARS value (0.296±0.01 𝜇gMDA/g) occurred in the broilerthigh nuggets with T
4samples. The highest TBARS mean
value (0.482 ± 0.03 𝜇gMDA/g) for broiler thigh nuggetswas reported at 2 months of storage while the lowest value(0.290 ± 0.01 𝜇gMDA/g) was recorded at the start of storage(Table 5). The combinations of 𝛼-lipoic acid with constantconcentration of 𝛼-tocopherol acetate resulted in less MDAproduction as compared to control samples. The same trend
of lowering TBARS values due to antioxidants was observedin previous study by Haak et al. [38] and Sohaib et al. [39] incooked meat products. Soyer et al. [40] observed increase inTBARS values of the meat products with cooking. SimilarlyPOVs of different treatments for broiler thigh nuggets variedsignificantly (𝑃 < 0.01). It is manifest from the data thatthe mean peroxide values of broiler thigh nuggets vary from1.02± 0.04meq O
2/kg of fat to 3.88± 0.4meq O
2/kg of fat for
different treatments during 2-month frozen storage (Table 5).The highest peroxide value (2.71 ± 0.1meq O
2/kg of fat) of
broiler thigh nuggets was recorded with control samples (T0)
while the lowest peroxide value (1.91 ± 0.2meq O2/kg of
fat) occurred in the broiler thigh nuggets from T4samples.
Peroxide values increase with storage days while frying ofnuggets also results in an increase in POV as cooking processand salt addition enhance lipid peroxidation, Mohamed etal. [41]. Thus freezing with subsequent frying resulted in anincrease in peroxide values of nuggets.These are in agreementwith Teets and Wenk [42] who state that duration of cookedchicken patties storage had significant effect on POV.Thomaset al. [43] have a similar finding regarding storage of cookedmeat products and increase in peroxide value.
3.5. Effect on Sensory Parameters of Nuggets. Sensory evalu-ation is generally used to predict the acceptability of a newproduct made through ingredient modification, Barbut [44].In cooking procedure color serves as a cue for the accep-tance of foods and is correlated with change in aroma andflavor. The results depicted that the color scores for different
Results are presented as mean ± SD (𝑛 = 3), whereas results in the same column with no superscripts in common differ significantly at 𝑃 < 0.01.T0: control, T1: control + 200mg vitamin E + 25mg 𝛼-lipoic acid/kg feed, T2: control + 200mg vitamin E + 50mg 𝛼-lipoic acid/kg feed, T3: control + 200mgvitamin E + 75mg 𝛼-lipoic acid/kg feed, and T4: control + 200mg vitamin E + 100mg 𝛼-lipoic acid/kg feed.
Table 5: Fatty acids profile (mg/100 g of fat) of chicken thigh meat.
Groups Fatty acids (mg/100 g of fat) of chicken thigh meat Fatty acids profile (%)12:0 14:0 16:0 16:1 18:0 18:1n9 18:2n6 18:3n3 20:4n6 20:5n3 22:6n3 SFA MUFA PUFA UFA
Results are presented as mean (𝑛 = 3), whereas results in the same column with no superscripts in common differ significantly at 𝑃 < 0.01.T0: control, T1: control + 200mg vitamin E + 25mg 𝛼-lipoic acid/kg feed, T2: control + 200mg vitamin E + 50mg 𝛼-lipoic acid/kg feed, T3: control + 200mgvitamin E + 75mg 𝛼-lipoic acid/kg feed, and T4: control + 200mg vitamin E + 100mg 𝛼-lipoic acid/kg feed.
Table 6: Sensory evaluation of chicken thigh meat nuggets.
Parameters T0 T1 T2 T3 T4
0 60 0 60 0 60 0 60 0 60Color 6.5 5.8 6.2 5.2 6.0 5.1 6.0 5.5 6.2 5.1Taste 7.7 6.8 6.8 5.4 7.0 5.9 7.2 6.2 7.8 6.8Flavor 7.9 7.6 7.1 6.6 7.0 6.4 7.3 6.8 7.9 7.6Appearance 8.1 7.1 7.4 6.8 6.1 6.0 6.8 6.1 8.0 7.5Acceptability 7.7 7.4 7.3 7.0 7.3 7.1 7.2 7.0 7.8 7.5Results are presented as mean (𝑛 = 3). T0: control, T1: control + 200mg vitamin E + 25mg 𝛼-lipoic acid/kg feed, T2: control + 200mg vitamin E + 50mg 𝛼-lipoic acid/kg feed, T3: control + 200mg vitamin E + 75mg 𝛼-lipoic acid/kg feed, and T4: control + 200mg vitamin E + 100mg 𝛼-lipoic acid/kg feed.
treatments vary significantly (𝑃 < 0.01). Yet, the interactiveeffect of treatments and storage of product showed significant(𝑃 < 0.01) effect on color scores of thigh nuggets.The highestmean score of color for broiler thigh nuggets was reported atthe start of storage while the lowest mean score was recordedat the end of 60-day storage (Table 6). The results of studyare in agreement with Naveena et al. [45] who stated thatcolor value of the chicken patties decreases with passage ofthe time. Similar results were presented by Fasseas et al. [23]and Sohaib et al. [39] in their respective studies where storagehas influence on color of meat products. The taste scoresof product also decreased with the progression of storageperiods and this decrease in taste scores may be attributedto peroxidation of PUFA. In earlier studies Biswas et al. [46]and Sohaib et al. [39] also reported the significant decrease intaste of the nuggets with the advancement of storage period.Flavor is an important parameter in sensory evaluation ofa food product and it is the combined perception of smell,
taste, and mouth feel. Flavor scores significantly decreasedwith progression of storage period. These results confirm thefindings of Devendra and Tanwar [47] who reported thatall the sensory quality values decreased significantly withthe advancement of storage period. However, antioxidantshave positive impact on the flavor of nuggets as nuggetsprepared from meat having higher concentration of lipoicacid were liked more by consumers. The appearance andoverall acceptability of nuggets decreased significantly withthe advancement in storage period. The previous researchersalso have a similar finding that sensory score decreased withpassage of storage time [39, 48, 49].
4. Conclusion
Alpha tocopherol and lipoic acid both are strong naturalantioxidants and their supplementation in broiler diet canenhance the antioxidant potential of thigh meat and meat
products. 100mg/kg feed dietary level of 𝛼-lipoic acid and𝛼-tocopherol acetate (200mg/kg feed) supplementation givesbest results and enhances the oxidative stability of meat andmeat products. Future researches are required for investi-gating the impact on meat products flavor volatiles and thedevelopment of antioxidants-enriched meat, which wouldbenefit the meat industry.
Conflict of Interests
The authors declare that there is no conflict of interestsregarding the publication of this paper.
References
[1] R. Ayerza, W. Coates, andM. Lauria, “Chia seed (Salvia hispan-ica L.) as an omega-3 fatty acid source for broilers: influence onfatty acid composition, cholesterol and fat content of white anddark meats, growth performance, and sensory characteristics,”Poultry Science, vol. 81, pp. 826–837, 2002.
[2] M. Terin, I. Yildirim, and K. Ciftci, “Chicken meat productionand poultry meat consumption in turkey and its progress,” inProceedings of the 2nd Mediterrean Summit of WPSA, pp. 215–220, 2010.
[3] B. M. Sitz, C. R. Calkins, D. M. Feuz, W. J. Umberger, andK. M. Eskridge, “Consumer sensory acceptance and value ofdomestic, Canadian, and Australian grass-fed beef steaks,” Jour-nal of Animal Science, vol. 83, no. 12, pp. 2863–2868, 2005.
[4] H.H.Musa,G.H.Chen, J.H.Cheng, E. S. Shuiep, andW.B. Bao,“Breed and sex effect on meat quality of chicken,” InternationalJournal of Poultry Science, vol. 5, no. 6, pp. 566–568, 2006.
[5] S. Im, F. Hayakawa, and T. Kurata, “Identification and sensoryevaluation of volatile compounds in oxidized porcine liver,”Journal of Agricultural and Food Chemistry, vol. 52, no. 2, pp.300–305, 2004.
[6] C. P. Baron and H. J. Andersen, “Myoglobin-induced lipid oxi-dation. A review,” Journal of Agricultural and Food Chemistry,vol. 50, no. 14, pp. 3887–3897, 2002.
[7] V. Petrovic, S. Marcncak, P. Popelka, L. Nollet, and G. Kovac,“Effect of dietary supplementation of trace elements on the lipidperoxidation in broiler meat assessed after a refrigerated andfrozen storage,” Journal of Animal and Feed Sciences, vol. 18, no.3, pp. 499–507, 2009.
[8] G. Bertelsen, M. Jakobsen, D. Juncher et al., “Oxidation, shelf-life and stability of meat and meat products,” in Proceedings ofthe 46th International Congress of Meat Science and Technology,pp. 516–524, Buenos Aires, Argentina, August-September 2000.
[9] A. E. D. Bekhit, G. H. Geesink, M. A. Ilian, J. D. Morton, andR. Bickerstaffe, “The effects of natural antioxidants on oxidativeprocesses and metmyoglobin reducing activity in beef patties,”Food Chemistry, vol. 81, no. 2, pp. 175–187, 2003.
[10] K. Z. Mahmoud and A. A. Hijazi, “Effect of vitamin A and/or Eon plasma enzymatic antioxidant systems and total antioxidantcapacity of broiler chickens challenged with carbon tetrachlo-ride,” Journal of Animal Physiology and Animal Nutrition, vol.91, no. 7-8, pp. 333–340, 2007.
[11] G. E. Onibi, “Dietary oil quality and vitamin E supplementationII: effect on carcass andmeat quality of broiler chickens,” BowenJournal of Agriculture, vol. 3, pp. 106–115, 2006.
[12] T. Srilatha, V. R. Redely, S. Qudratullah, and M. V. L. N.Raju, “Effect of alpha-lipoic acid and vitamin e in diet on the
performance, antioxidation and immune response in broilerchicken,” International Journal of Poultry Science, vol. 9, no. 7,pp. 678–683, 2010.
[13] M. S. Arshad, F. M. Anjum, M. I. Khan, M. Shahid, S. Akhtar,and M. Sohaib, “Wheat germ oil enrichment in broiler feedwith 𝛼-lipoic acid to enhance the antioxidant potential and lipidstability of meat,” Lipids in Health and Disease, vol. 12, article164, 2013.
[14] M. Senevirathne, S.-H. Kim, N. Siriwardhana, J.-H. Ha, K.-W.Lee, and Y.-J. Jeon, “Antioxidant potential ofecklonia cavaonreactive oxygen species scavenging, metal chelating, reducingpower and lipid peroxidation inhibition,” Food Science andTechnology International, vol. 12, no. 1, pp. 27–38, 2006.
[15] W. Brand-Williams, M. E. Cuvelier, and C. Berset, “Use of a freeradical method to evaluate antioxidant activity,” LWT—FoodScience and Technology, vol. 28, no. 1, pp. 25–30, 1995.
[16] A. Asghar, J. I. Gray, D. J. Buckley, C. F. Lin, A. M. Booren,and C. J. Flegal, “Effects of dietary oils and alpha-tocopherolsupplementation on lipid composition and stability of broiler,”Journal of Food Science, vol. 54, pp. 375–389, 1989.
[17] S. Satoh, T. Toyo’oka, T. Fukushima, and S. Inagaki, “Simultane-ous determination of𝛼-lipoic acid and its reduced formbyhigh-performance liquid chromatography with fluorescence detec-tion,” Journal of Chromatography B: Analytical Technologies inthe Biomedical and Life Sciences, vol. 854, no. 1-2, pp. 109–115,2007.
[18] A. Asghar, C. F. Lin, J. I. Gray, D. J. Buckley, A. M. Booren, andC. J. Flegal, “Effects of dietary oils and alpha tocopherol supple-mentation on membranal lipid oxidation in broiler meat,”Journal of Food Science, vol. 55, pp. 46–50, 1990.
[19] N. C. Shantha and E. A. Decker, “Rapid, sensitive, iron-basedspectrophotometric methods for determination of peroxidevalues of food lipids,” Journal of AOAC International, vol. 77, no.2, pp. 421–424, 1994.
[20] W. W. Christie, “Gas chromatographic analysis of fatty acidmethyl esters with high precision,” Lipid Technology, vol. 3, pp.97–98, 2011.
[21] R. G. D. Steel, J. H. Torrie, and D. Dickey, Principles and Proce-dures of Statistics: A Biometrical Approach, McGraw Hill, NewYork, NY, USA, 3rd edition, 1997.
[22] M. S. Arshad, F. M. Anjum, A. Asghar et al., “Lipid stabilityand antioxidant profile of microsomal fraction of broiler meatenrichedwith𝛼-lipoic acid and𝛼-tocopherol acetate,” Journal ofAgricultural and Food Chemistry, vol. 59, no. 13, pp. 7346–7352,2011.
[23] M. K. Fasseas, K. C. Mountzouris, P. A. Tarantilis, M. Polissiou,and G. Zervas, “Antioxidant activity in meat treated withoregano and sage essential oils,” Food Chemistry, vol. 106, no.3, pp. 1188–1194, 2008.
[24] B. Min, K. C. Nam, J. Cordray, and D. U. Ahn, “Endogenousfactors affecting oxidative stability of beef loin, pork loin, andchicken breast and thigh meats,” Journal of Food Science, vol.73, no. 6, pp. C439–C446, 2008.
[25] N. A. Botsoglou, D. J. Fletouris, P. Florou-Paneri, E. Christaki,and A. B. Spais, “Inhibition of lipid oxidation in long-termfrozen stored chicken meat by dietary oregano essential oil and𝛼-tocopheryl acetate supplementation,” Food Research Interna-tional, vol. 36, no. 3, pp. 207–213, 2003.
[26] J. Fernandez, J. A. Perez-Alvarez, and J. A. Fernandez-Lopez,“Thiobarbituric acid test for monitoring lipid oxidation inmeat,” Food Chemistry, vol. 59, no. 3, pp. 345–353, 1997.
[27] V. Cardenia, M. T. Rodriguez-Estrada, F. Cumella, L. Sardi, G.Della Casa, and G. Lercker, “Oxidative stability of pork meatlipids as related to high-oleic sunflower oil and vitamin E dietsupplementation and storage conditions,”Meat Science, vol. 88,no. 2, pp. 271–279, 2011.
[28] R. Levermore, “Rancidity in fresh and stored pork products,”Meat International, vol. 14, pp. 16–18, 2004.
[29] H. R. Gheisari, “Correlation between acid, TBA, peroxide andiodine values, catalase and glutathione peroxidase activities ofchicken, cattle and camel meat during refrigerated storage,”Veterinary World, vol. 4, no. 4, pp. 153–157, 2011.
[30] B. M. Rezk, G. R. M. M. Haenen, W. J. F. van der Vijgh, and A.Bast, “Lipoic acid protects efficiently only against a specific formof peroxynitrite-induced damage,” Journal of Biological Chemis-try, vol. 279, no. 11, pp. 9693–9697, 2004.
[31] R. Parveen, A. Asghar, F. M. Anjum, M. I. Khan, M. S. Arshad,and A. Yasmeen, “Selective deposition of dietary 𝛼-Lipoic acidin mitochondrial fraction and its synergistic effect with 𝛼-Tocoperhol acetate on broiler meat oxidative stability,” Lipids inHealth and Disease, vol. 12, no. 1, article 52, 2013.
[32] H. Moini, O. Tirosh, Y. C. Park, K.-J. Cho, and L. Packer, “R-𝛼-lipoic acid action on cell redox status, the insulin receptor, andglucose uptake in 3T3-L1 adipocytes,” Archives of Biochemistryand Biophysics, vol. 397, no. 2, pp. 384–391, 2002.
[33] S. Celik and A. Ozkaya, “Effects of intraperitoneally adminis-tered lipoic acid, vitaminE, and linalool on the level of total lipidand fatty acids in guinea pig brain with oxidative stress inducedby H2O2,” Journal of Biochemistry and Molecular Biology, vol.
35, no. 6, pp. 547–552, 2002.[34] L. Cortinas, C. Villaverde, J. Galobart, M. D. Baucells, R.
Codony, andA.C. Barroeta, “Fatty acid content in chicken thighand breast as affected by dietary polyunsaturation level,” PoultryScience, vol. 83, no. 7, pp. 1155–1164, 2004.
[35] N. Kolsarıcı, K. Candogan, and I. T. Akoglu, The Influenceof Dietary Fish Oil and Vitamin E on the Fatty Acid Profileand Oxidative Stability of Frozen Stored Chicken Breast Meat,Department of Animal Nutrition and Feed Science, NationalResearch Institute of Animal Production, Balice, Poland, 2010.
[36] R. Bou, F. Guardiola, A. Tres, A. C. Barroeta, and R. Codony,“Effect of dietary fish oil, 𝛼-tocopheryl acetate, and zinc supple-mentation on the composition and consumer acceptability ofchicken meat,” Poultry Science, vol. 83, no. 2, pp. 282–292, 2004.
[37] M. S. Arshad, F. M. Anjum, M. I. Khan, and M. Shahid,“Wheat germ oil and 𝛼-lipoic acid predominantly improve thelipid profile of broiler meat,” Journal of Agricultural and FoodChemistry, vol. 61, no. 46, pp. 11158–11165, 2013.
[38] L. Haak, K. Raes, S. van Dyck, and S. de Smet, “Effect ofdietary rosemary and 𝛼-tocopheryl acetate on the oxidativestability of raw and cooked pork following oxidized linseed oiladministration,”Meat Science, vol. 78, no. 3, pp. 239–247, 2008.
[39] M. Sohaib, F. M. Anjum, M. I. Khan, M. S. Arshad, and M.Shahid, “Enhancement of lipid stability of broiler breast meatandmeat products fed on alpha lipoic acid and alpha tocopherolacetate supplemented feed,” Lipids in Health and Disease, vol. 11,article 57, 2012.
[40] A. Soyer, B. Ozalp, U. Dalmis, and V. Bilgin, “Effects of freezingtemperature and duration of frozen storage on lipid and proteinoxidation in chicken meat,” Food Chemistry, vol. 120, no. 4, pp.1025–1030, 2010.
[41] A. Mohamed, B. Jamilah, K. A. Abbas, and R. Abdul Rahman,“A review on lipid oxidation of meat in active and modified
atmosphere packaging and usage of some stabilizers,” Journalof Food, Agriculture and Environment, vol. 6, no. 3-4, pp. 76–81,2008.
[42] A. S. Teets and L. M. Were, “Inhibition of lipid oxidation inrefrigerated and frozen salted raw minced chicken breasts withelectron beam irradiated almond skin powder,” Meat Science,vol. 80, no. 4, pp. 1326–1332, 2008.
[43] R.Thomas, A. S. R. Anjaneyulu, Y. P.Gadekar,H. Pragati, andN.Kondaiah, “Effect of comminution temperature on the qualityand shelf life of buffalo meat nuggets,” Food Chemistry, vol. 103,no. 3, pp. 787–794, 2007.
[44] S. Barbut, Poultry Products Processing: An Industry Guide, CRCPress, Boca Raton, Fla, USA, 2002.
[45] B. M. Naveena, A. R. Sen, S. Vaithiyanathan, Y. Babji, and N.Kondaiah, “Comparative efficacy of pomegranate juice, pome-granate rind powder extract and BHT as antioxidants in cookedchicken patties,” Meat Science, vol. 80, no. 4, pp. 1304–1308,2008.
[46] S. Biswas, A. Chakraborty, and S. Sarkar, “Comparison amongthe qualities of patties prepared from chicken broiler, spent henand duck meats,” The Journal of Poultry Science, vol. 43, no. 2,pp. 180–186, 2006.
[47] K. Devendra and V. K. Tanwar, “Utilization of clove powder asphytopreservative for chicken nuggets preparation,” Journal ofStored Products Research, vol. 2, pp. 11–14, 2011.
[48] J. A. Ruiz, A. M. Perez-Vendrell, and E. Esteve-Garcıa, “Effect of𝛽-carotene and vitamin E on oxidative stability in leg meat ofbroilers fed different supplemental fats,” Journal of Agriculturaland Food Chemistry, vol. 47, no. 2, pp. 448–454, 1999.
[49] R. S. Filgueras, P. Gatellier, L. Aubry et al., “Colour, lipidand protein stability of Rhea americana meat during air- andvacuum-packaged storage: influence of muscle on oxidativeprocesses,”Meat Science, vol. 86, no. 3, pp. 665–673, 2010.
